Improvement of TE-polarized emission in type-II InAlN–AlGaN/AlGaN quantum well**Project supported by the Talent Introduction Project of Nantong University, China (Grant No. 03081055), the National Natural Science Foundation of China (Grant Nos. 61874168 and 61505090), Top-notch Academic Programs Project of Jiangsu Higher Education Institutions, China (Grant No. PPZY2015B135), the Six Top Talents of Jiangsu Province, China (Grant No. 2016-XCL-052), the Natural

Abstract

The optical properties of the type-II lineup InxAl1−xN–Al0.59Ga0.41N/Al0.74Ga0.26N quantum well (QW) structures with different In contents are investigated by using the six-by-six K–P method. The type-II lineup structures exhibit the larger product of Fermi–Dirac distribution functions of electron and hole and the approximately equal transverse electric (TE) polarization optical matrix elements ( for the c1–v1 transition. As a result, the peak intensity in the TE polarization spontaneous emission spectrum is improved by 47.45%–53.84% as compared to that of the conventional AlGaN QW structure. In addition, the type-II QW structure with has the largest TE mode peak intensity in the investigated In-content range of 0.13–0.23. It can be attributed to the combined effect of and for the c1–v1, c1–v2, and c1–v3 transitions.